Acinetobacter

• What type of infections have Acinetobacter species been increasingly associated with in recent years?

  Nosocomial infections
• Where can Acinetobacter be commonly found in the environment?

  In drinking water, surface water, soil, and sewage
• Which species of Acinetobacter can cause serious infections primarily in very ill hospital patients?

  1. baumannii
• What are the most common types of infections caused by Acinetobacter?

  Pneumonia, bacteremia, wound infections, and urinary tract infections
• What is a significant challenge in treating hospital-adapted Acinetobacter infections?

  They are sometimes resistant to antibiotics
• In which family is Acinetobacter currently classified?

  Moraxellaceae
• What are the morphological characteristics of Acinetobacter bacteria?

  Non-motile, oxidase negative, gram-negative coccobacilli
• What are the groups called that Acinetobacter species are classified into based on DNA-DNA hybridization?

  Genomospecies
• What are some named genomospecies of Acinetobacter?

  • A. calcoaceticus
  • A. baumannii
  • A. haemolyticus
  • A. junii
  • A. johnsonii
  • A. lwoffii
• What is a challenge in separating saccharolytic strains of Acinetobacter using phenotypic tests?

  Some laboratories report them as A. calcoaceticus or A. baumannii complex
• What is the Gram stain morphology of Acinetobacter?

  Gram-negative coccobacilli often appearing as diplococci
• How do Acinetobacter and Neisseria gonorrhoeae appear in Gram stains?

  Acinetobacter may initially appear as gram-positive cocci in direct smears
• What are the related non-fermenters to Acinetobacter?

  • Stenotrophomonas
  • Burkholderia
  • Pseudomonas
• What is the appearance of Acinetobacter colonies on blood agar after 24 hours of incubation?

  1. 2 mm in diameter, translucent to opaque, convex, and entire
• What is the biochemical profile of Acinetobacter?

  Oxidase negative, nitrate negative, catalase positive, non-fermentative, and non-motile
• What is the characteristic of A. baumannii in terms of carbohydrate metabolism?

  1. baumannii is saccharolytic and acidifies most carbohydrates
• How can A. johnsonii be differentiated from other Acinetobacter species?

  By its failure to grow at 37 degrees Celsius
• What role do Acinetobacter spp. play in hospitalized patients?

  They play a significant role in colonization and infection
• Which species of Acinetobacter is most commonly found in human clinical specimens?

  1. baumannii
• What is the significance of A. lwoffii, A. johnsonii, and A. radioresistens in relation to human skin?

  They are non-saccharolytic Acinetobacter that occur as natural inhabitants of human skin
• How many species of Acinetobacter are there, and what proportion of infections are due to A. baumannii?

  32 species, with more than 2/3 of infections due to A. baumannii
• What are the intrinsic and acquired factors contributing to Acinetobacter's pathogenesis?

  Intrinsic and acquired multi-drug resistance
• What are the common types of hospital-acquired Acinetobacter infections?

  • Ventilator-associated pneumonia
  • Urinary tract infections
  • Bloodstream infections
  • Secondary meningitis
  • Skin/wound infections
  • Endocarditis
  • CAPD-associated peritonitis
  • Ventriculitis
• What percentage of all ventilator-associated pneumonia cases is accounted for by Acinetobacter?

  1. 25 percent
• What are some risk factors for Acinetobacter ventilator-associated pneumonia?

  Advanced age, chronic lung disease, immunosuppression, surgery, use of antimicrobial agents, invasive devices, prolonged ICU stay
• What is the most common source of Acinetobacter bloodstream infections?

  Respiratory tract infection
• What are some predisposing factors for Acinetobacter bloodstream infections?

  Malignancy, trauma, burns, surgical wound infections, neonates, low birth weight, need for mechanical ventilation
• What is the rank of Acinetobacter baumannii in terms of bloodstream infections per 10,000 admissions?

  9th place with 0.6 BSI per 10,000 admissions
• What is the inflammatory response to Acinetobacter bloodstream infections?

  Sepsis, severe sepsis, and septic shock
• What are the common risk factors for Acinetobacter meningitis?

  Ventriculostomy and heavy use of antibiotics in the neurosurgical ICU
• What are the common sources of Acinetobacter outbreaks?

  • Organ site
  • Genetic typing
  • Hospital location
  • Common source outbreak with respiratory site predominance
  • Common source outbreak without respiratory site predominance
  • Respiratory site outbreaks without an identified common source
  • Non-respiratory site outbreaks without an identified common source
• What nickname was given to Acinetobacter due to its association with military infections in Iraq?

  Iraqibacter
• What was the significant finding regarding Acinetobacter outbreaks from 1977 to 2000?

  The majority of reports occurred over the last 9 years
• What are the settings where Acinetobacter outbreaks commonly occur?

  • Medical ICU
  • Surgical ICU
  • Shock-Trauma ICU
  • Medical Wards
  • Nursery
  • Mixed Medical/Surgical ICU
  • Burn and Plastic Surgery Wards
• What are the reservoirs of Acinetobacter in the hospital environment?

  Bed rails, bedside tables, ventilators, infusion pumps, mattresses, pillows, air humidifiers, patient monitors, X-ray view boxes, curtain rails, equipment carts, sinks, and floor mops
• What factors promote the transmission of Acinetobacter in the ICU?

  Long survival time on inanimate surfaces and extensive environmental contamination
• How long can Acinetobacter survive on inanimate surfaces?

  In vitro survival time can be up to 329 days
• What is the primary mode of transmission of Acinetobacter in hospital settings?

  Direct or indirect contact, often via contaminated hands of healthcare workers
• What are the reservoirs of Acinetobacter?

  Environmental contamination
• What are common environmental surfaces contaminated with Acinetobacter in healthcare settings?

  • Bed rails
  • Bedside tables
  • Ventilators
  • Infusion pumps
  • Mattresses
  • Pillows
  • Air humidifiers
  • Patient monitors
  • X-ray view boxes
  • Curtain rails
  • Curtains
  • Equipment carts
  • Sinks
  • Ventilator circuits
  • Floor mops